JUMO Ex-i, Safety Manual

Page: 23 / 32

23
6 Safety-related applications
6.8 Failure rates
Non-inverting operation
Inverting operation
Low-demand mode
The PFD
avg
values for 1, 2, and 3 years are within the permissible range for SIL 2 according to table 2
from IEC/EN 61508-1. They meet the requirement of not covering more than 10 % of the safety circuit
or are better than or equal to 1.00 × 10
-3
.
The PFD
avg
values for 4 and 5 years are within the permissible range for SIL 2 according to table 2 from
IEC/EN 61508-1. However, they do meet the requirement of not covering more than 10 % of the safety
circuit or are not better than or equal to 1.00 × 10
-3
.

S

DD

DU
SFF DC
avg
MTBF Function
187 FIT 6 FIT 48 FIT 80 % 9 % 227 years Normally open contact
(RNO) C1
252 FIT 6 FIT 83 FIT 76 % 7 % 189 years Normally open contact
(RNO) C2
177 FIT 6 FIT 83 FIT 76 % 9 % 227 years Normally closed contact
(RNC) C5
232 FIT 6 FIT 103 FIT 70 % 6 % 189 years Normally closed contact
(RNC) C6

S

DD

DU
SFF DC
avg
MTBF Function
189 FIT 6 FIT 106 FIT 79.4 % 9 % 227 years Normally open contact
(RNO) C3
254 FIT 56 FIT 86 FIT 75.2 % 5 % 189 years Normally open contact
(RNO) C4
179 FIT 6 FIT 61 FIT 75.3 % 9 % 227 years Normally closed contact
(RNC) C7
234 FIT 6 FIT 106 FIT 69.4 % 5 % 189 years Normally closed contact
(RNC) C8
T
[PROOF]
= 1 year 2 years 3 years 4 years 5 years Function
PFD
avg
= 2.1 × 10
-4
4.2 × 10
-4
6.3 × 10
-4
8.4 × 10
-4
1.05 × 10
-3
Normally open contact
(RNO) C1
PFD
avg
= 3.63 × 10
-4
7.26 × 10
-4
Normally open contact
(RNO) C2
PFD
avg
= 2.22 × 10
-4
4.44 × 10
-4
6.66 × 10
-4
8.88 × 10
-4
1.11 × 10
-3
Normally open contact
(RNO) C3
PFD
avg
= 3.75 × 10
-4
7.5 × 10
-4
Normally open contact
(RNO) C4
PFD
avg
= 2.54 × 10
-4
5.08 × 10
-4
7.62 × 10
-4
1.16 × 10
-3
Normally closed contact
(RNC) C5
PFD
avg
= 4.51 × 10
-4
9.02 × 10
-4
Normally closed contact
(RNC) C6
PFD
avg
= 2.65 × 10
-4
5.3 × 10
-4
7.95 × 10
-4
1.6 × 10
-3
Normally closed contact
(RNC) C7
PFD
avg
= 4.64 × 10
-4
9.28 × 10
-4
Normally closed contact
(RNC) C8